Measuring Relevance and Popularity
Here’s a quick history lesson for you: did you know that modern commercial search engines rely on the science of information retrieval (IR)? IR has been a science since around the 1950s, when computer-powered retrieval systems first came into use in libraries, research facilities and government labs. Early in the development of search systems, IR scientists realized that two critical components made up the majority of search functionality:
Relevance - the degree to which the content of a document matched the user’s query intention and terms. The relevance of a document increases if the terms or phrase queried by the user occurs multiple times and shows up in the title of the work or in important headlines or subheads.
Popularity - the relative importance, measured via citation (the act of one work referencing another, as often occurs in academic and business documents) of a given document that matches the user’s query. The popularity of a given document increases every time another document references it.
These two items were translated to Web search 40 years later in what search engine marketers now know as document analysis and link analysis.